银狐气味对根田鼠觅食的影响

以银狐气味作为捕食风险源,对根田鼠提供花生、玉米、兔颗粒饲料3种食物项目,测定捕食风险对根田鼠觅食行为的影响。结果表明,银狐气味对根田鼠雄体的食物摄入量、觅食时间、觅食频次以及能量摄入并无显著影响,但对于雌体,银狐气味可极显著增加其24h内对食物的摄入总量（P<0.01）,但对其食物摄入量、觅食时间和觅食频次均无显著影响。银狐气味条件下,根田鼠个体的最终体质量未发生显著变化。     

The use of eugenol against Aeromonas hydrophila and its effect on hematological and immunological parameters in silver catfish (Rhamdia quelen)

The aim of this study was to evaluate the activity of eugenol against the fish pathogen Aeromonas hydrophila and eugenol's effect on hematological and natural immune parameters in silver catfish (Rhamdia quelen). In vitro, eugenol showed weak activity against A. hydrophila, but in vivo, at a subinhibitory concentration (10 mg L^?1), it promoted survival in infected silver catfish. Eugenol (50 μg mL^?1) reduced the hemolytic activity of A. hydrophila supernatant in vitro in fish erythrocytes. Subjecting catfish to eugenol baths (5 and 10 mg L^?1) for five days did not alter the hematological and immunological parameters studied in this work. Based on these results, eugenol can be used to treat or prevent bacterial diseases in fish.     

烟粉虱对青萝卜白心的影响

烟粉虱危害青萝卜造成其叶脉、表皮及木质部变白（白心）。随着接虫密度的增大。青萝卜叶脉变白株率、外表皮退绿株率和白心率依次增加，单株有虫40头以下时，青萝卜白心率在10％以下。     

云开山国家级自然保护区鸟类新纪录——白鹇

2019年3—5月,利用红外相机开展云开山国家级自然保护区野生动物监测的过程中,拍摄到雄性白鹇的影像,栖息地以常绿阔叶林为主。经查阅文献和实地走访,证实白鹇在粤西地区确实有存在,由此白鹇在广东省境内的分布也进一步往西推移。     

鲢染色体图象电脑自动核型分析↑（*）

应用ＩＢＡＳ－２０００图象分析系统对鲢（Ｈｙｐｏｐｈｔｈａｌｍｉｃｈｔｈｙｓｍｏｌｔｔｒｉｘ）染色体进行自动核型分析，获得比较准确的鲢染色体相对长度、臂比、着丝点指数数据和核型标准图象信息。染色体组型２ｎ＝４８，核型公式１８ｍ＋２２ｓｍ＋８ｓｔ，总臂数（ＮＦ）为８８。与常规方法比较，该方法重现性好，准确性高，速度快，图形和数据能永久保存，便于建立鱼类染色体标准图形信息库。     

银狐主要繁殖性状的重复力分析

通过对银狐主要繁殖性状重复力的估计和分析,为选育和改良银狐提供理论基础。利用具有2次或2次以上产仔记录的248只母银狐627个繁殖成绩和51只公狐211个繁殖成绩记录,估计了银狐主要繁殖性状的重复力。产仔母狐胎平均产仔数、胎平均断奶活仔数、母狐配种日期、母狐妊娠期的重复力分别为0.114、0.007、0.270和0.206,公狐与配母狐平均产仔数、与配母狐平均断奶活仔数、与配母狐受胎率的重复力分别为0.108、0.303和0.206。母银狐繁殖能力和公狐与配母狐的平均产仔数、受胎率等性状主要受非遗传因素所控制。     

脆化异育银鲫(Carassius auratus gibelio Bloch)生态、生理学研究

比较研究了标准脆化的脆肉鲫(异育银鲫)与普通异育银鲫的生理生态学特性差异。脆肉鲫的横轴/纵轴、净重/总重、脏重/总重分别为0.5868±0.0301,0.8407±0.0272,0.1612±0.0248,而普通银鲫则分别为0.5107±0.0423,0.8065±0.0097,0.1935±0.0097,脆肉鲫与普通银鲫的形态学指标差异极显著(F值F0.01)。饲料中蚕豆营养成份的摄取是直接导致异育银鲫脆化的原因,并影响银鲫的正常生理生态学指标,脆肉鲫(异育银鲫)与普通异育银鲫体长(L)与体重(W)关系的体征指数方程明显不同,分别为W普通鲫=0.00000016L3.3375,W脆肉鲫=0.00000378L3.9683,肥满度系数分别为K普通鲫=0.0023,K脆肉鲫=0.0035。试验表明,脆肉鲩养殖中混养脆肉鲫的最佳方案为放养规格4cm/尾、密度2250尾/hm2,力争特定生长率在两年内平均值达到1.3488±0.0212水平,脆化度为0.41kg/cm2以上的合格脆肉鲫。此外,脆肉鲩养殖场内几乎所有摄食蚕豆的鱼类都会出现不同程度的脆化现象。文章还就进一步完善脆肉鲫养殖生产规程,合理调控放养密度和养殖水环境因子,提高脆肉鲫混养技术和养殖效益进行了讨论。     

Genetic variation and inheritance in a 9 × 9 diallel in silver birch (Betula pendula)

A complete diallel cross was made among nine Betula pendula trees growing in a natural population and a trial was planted on agricultural soil at one site. This exceptional trial has provided estimates of genetic parameters that can only be estimated in complete diallels. Traits measured were height and diameter during a period of 37 years, and assessments were made of bud burst, leaf abscission and rust infection at the early ages. All traits showed genetic variation and the variance components of general combining ability (GCA) effects were dominating, with heritability estimates of 0.16 and 0.23 for height and diameter at age six years. The best-growing families could be identified at that age. At age 37 years, when the trial had been thinned twice, the offspring from the highest and lowest ranked parent for growth contributed with 19% and 6% of the total volume of the stand, respectively. The GCA effects were also highly significant for the assessment traits, but with an interaction with year for bud burst. High values of estimates of genetic correlations proved that bud burst, leaf abscission and rust infection are interrelated, and also to some extent with growth traits. Families with an early bud burst were tallest, were less affected by the rust fungus and kept their leaves later in the autumn.     

枳属36份特异种质的AFLP指纹图谱构建与分析

 从40个Pstl／MseI酶切的AFLP引物对中筛选出多态性高的7个，对36份枳属特异种质进行了指纹分析。7个引物对共获得539条带，其中146条带具有多态性。各种质材料之间的遗传相似性在0．23～ 0．98之间，只需结合其中的3个引物对即可区分所有的材料。根据7个AFLP引物对所得谱带的聚类分析表明，聚类结果与地理来源没有明显的联系，这可能正反映了近时间内地区之间枳资源的频繁交流。     

棉花银染mRNA差异显示体系优化研究

mRNA差异显示技术(DDRT-PCR)是分离差异表达基因的有效方法。以陆地棉组织培养过程中不同时期愈伤组织为材料,对RNA提取、PCR反应体系、银染条件等影响mRNA差异显示的关键因素进行优化试验,建立了一套适合棉花组织培养的mRNA差异显示体系。最终确定了优化体系(50μL)为:随机引物0.4μmol/L,锚定引物0.4μmol/L,dNTP 250μmol/L,Mg2+1.5 mmol/L,Taq酶1.5 U,退火温度为39.3℃。利用优化后的体系对材料进行扩增,扩增产物特异性好、条带清晰、背景干净。该体系简便、快捷、灵敏、高效,可用于分离差异表达基因。